These Training Aids are one of a kind Revolutionary patented designs that give you fast results no matter what level you play at. You will Improve your whole game after just minutes.It's fun to win... So have more of fun with ProTrainer Tennis Innovations Products. See our products at www.ptwinsock.com Contact me at firstname.lastname@example.org. The WinSock is a training weight that slides on and off your racquet quickly and easily. Unlike other sport training weights that are limited in real feel and timing because your not able to hit the ball, the WinSock can be used while actually hitting the tennis ball and your regular shots thus allowing you to focus on timing and hitting the through the sweet spot, and at the same time, strengthening your tennis muscles. The small amount of weight is positioned at the center point of balance so it does not throw off timing and is used to hit all shots during your warm-up or practice sessions. After your warm-up; you remove the WinSock and you get instant powerful results including more racquet speed, stronger wrist and forearm muscles for better racquet control, more endurance, more penetrating ground strokes, faster reflexes and a higher level of overall confidence.